During road resurfacing, at least a portion of the upper surface of the roadway is removed by specialized equipment to allow a new layer of asphalt to be deposited. A cold planing operation, which may also be referred to as a milling operation, asphalt milling, a plunge cut operation, or profiling, can be carried out at various depths into the road surface. Typically, the asphalt removed from the upper surface is collected for recycling. Cold planing may also be used to control heights and clearances of other road structures, such as curb reveals, manhole and catch basin heights, shoulder and guardrail heights, overhead clearances, and the like in both finished and unfinished road surfaces.
A typical cold planing machine that performs such operations includes a rotating drum encased in a housing, the drum being used for removing or grinding the road surface. The housing prevents debris removed from the road surface from scattering. Further, design of the housing facilitates in transport of the debris for collection. For example, a conveyer system adjacent to the housing collects the road debris at one end of a conveyer belt and ejects the debris to a collection truck at the opposite end of the conveyer belt.
One such planing operation is milling, where the cold planer machine is advancing down the road, and the rotating drum is at a height low enough to interact with the road surface. During such a milling operation, the cold planer machine removes the desired thickness from the road surface as it progresses down the road. Another such planing operation is a plunge cut operation, where the cold planer machine is stationary (e.g., not translating forward or backward), the drum is rotating and being lowered into the road surface. During such a plunge cut operation, the surface of the roadway at one location is removed as the rotating drum is lowered into the road surface.
During the operations removing the road surface, the cold planer machine utilizes fluid spray for lubrication of the rotating drum as it interacts with the road surface and to minimize dust creation. The fluid, such as water, is typically carried onboard the cold planer machine in an onboard retention tank. Excessive use of fluid results in more frequent needs to refill the onboard retention tank and waste of fluid. On the other hand, underuse of fluid spray during operations may result in inadequate lubrication of the drum and excessive dust formation.
U.S. Pat. No. 9,371,618 discloses systems and methods for cold planer spray systems. In particular, the '618 patent discloses operations of pump signals and manifold operations in implementing spray control during cold planer operations. However, there is still a need for automatic water spray milling for cold planer operations.